what is this high voltage display device called?

What I'm thinking of is not a plasma globe, although, like the globe, it too is intended primary for display. If I were to describe it, I remember it being made out of glass, maybe 1-2 feet in diameter, and nearly flat in thickness. Electric discharges from the center to the edge of the glass and looked a lot like lightning. I remember these devices being used in Star Trek The Next Generation used behind the heads of Borg drones. They used to be in Spencers too available for purchase.

Reply to
Branden
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Reply to
Branden

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Ok, I found it. Luminglas or plasma plate or plasma disk. Wow, they are really costly now. The ones in Spencer's 20 years ago were around $40 for 15 inch size... now it looks like at least 3 times that!

Reply to
Branden

Inflation innit. A price tripling over 20 years doesn't seem that unlikely.

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Reply to
Cursitor Doom

An ordinary clear-glass incendescent bulb makes some nice sparks inside if you apply HF-HV to one side of the filament.

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John Larkin         Highland Technology, Inc 

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Reply to
jlarkin

Much too high. In the UK, inflation from 1999 to 2019 accounted for a price rise of about 72%. You have to go back to 1985 for inflation to triple the value in 2019.

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Jeff
Reply to
Jeff Layman

Wow, they

around

Looks like I should have bought one at the time. There's now way I'll shell out 4x for it now. Oh well.

Reply to
Branden

If you're talking a "plasma globe", yes I have one of those. It is about 14" diameter and cost me $19 at Walmart about 15 years ago. However, I see that even those in many cases appear to be somewhat higher in price, but certainly not nearly as high as the luminglas!

Reply to
Branden

No, I meant an ordinary light bulb.

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John Larkin         Highland Technology, Inc 
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Reply to
John Larkin

John means a lightbulb with a tungsten filament in it which burns very brightly when a current is passed through it. You have to have attained great age, like John and I, in order to remember such obsolete atrocities.

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Reply to
Cursitor Doom

But don't heat the filament, just apply a lot of high voltage, high frequency stuff to it.

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John Larkin         Highland Technology, Inc 
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Reply to
John Larkin

Yes, Ive applied clear incandescents to a HV source too! It can produce a different display from an actual plasma globe depending on bulb vacuum or type of gas used. One has to be very careful of the 25 watt incandescents though if applied to high voltage. Some of those used to produce x-rays because they were vacuumed but not backfilled! I think manufacturers have corrected this nowadays, but 20 years ago they were not backfilled.

Reply to
Branden

Like putting one in the microwave. To protect the microwave, also put a glass of water inside. The lamp does not need to be in working order.

Reply to
Sjouke Burry

Part of that price is the size. If you must have a 15" disk, it's going to cost you. 6" are about $25 to $30.

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Paul Hovnanian P.E.

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Just wanted to update that I now actually have thee of the Luminglas displays! Although eBay prices are out of this world, I found all of these either on Facebook Marketplace or Craigslist and all for less than

$50 each. A lot more reasonably priced! I remember them charging anywhere from $25-50 back in the late 90's early 00's when they were in Spencer's and elsewhere. If they are indeed collector items now, I may have three chances in the future to sell if I ever grow tired of them.

Reply to
Branden

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